Computers are very powerful tools for presenting information to users. Often, computers present information visually, on a display screen or other visual presentation device. However, many users of computers are blind, visually impaired, dyslexic or have low-vision or learning disabilities, or are sighted users who simply want or need to use a computing device without looking at the device during operation. These users can benefit from accessibility devices that present information in nonvisual ways. One way a computer presents information a nonvisual way is with a text-to-speech transducer that reads aloud the content of a display screen.
Current text-to-speech systems work reasonably well with linear prose, like that found in an electronic message or novel. Unfortunately, existing text-to-speech systems remain cumbersome and difficult to use for presenting symbolic expressions such as mathematical, scientific, or chemical expressions, formulas, or equations. Precise navigation and presentation of symbolic expressions is often difficult or not possible, thereby creating a significant cognitive burden on a user with impaired vision.
Accordingly, there is a need for computer-implemented techniques for presenting symbolic expressions in a more accessible way. Such techniques may complement or replace existing computer-implemented techniques for presenting information. Such techniques reduce the cognitive burden on a user with impaired vision and produce a more accessible and efficient human-machine interface.